Motor-driving unit for sewing machines



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F 12 9 H. MAEMKN MOTOR DRIVING. UNIT FOR SEWING MACHINES Filed Jan. 16, 1923 5 Sheets-Sheet J1 lflgENTOR 14M i ATTORNEY5 Feb. 12, 192% H. MAIMHN MOTOR DRIVING UNIT FOR SEWING mcnnws Filed Jan. 16, 1923' s Sheets-Sheet 2 INV NTOR ATTORNEY6 Feb. 12, 1924. 1,483,103

H. MAIMIN MOTOR DRIVING UNIT FOR SEWING MACHINES Filed Jan. 16, 1923 3 Sheets-Sheet 5 i i I 1 l I i I l l- I I i I 1 I 1 I I I 1 E -25| 1 Y I I '1 I /35 I Q l t v 1 I I ra u /3 76 big: 7 I A9 3g; I PM If s n 0% i I 1 (9 Y INVENTOR ATTORNEYS Patented Feb, 12, 1924.

HYMAN MAIMIN, or NEVI YORK, 1v. Y.

MOTOR-DRIVING UNIT FORSEWING IIIAGHINES.

Application filed January 16, 1923. 7 Serial No. 612,938.

To all whom it may-concern.

Be it known that I, HYMAN l\L\IMIN, a citizen of the United States, residing at 251 West 19th Street. New York city, in the county of New York, State of New York, have invented certain new and useful Improvements in Motor-Driving Units for Sewing Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to motor drives pri marily designed for use in connection with sewing machines, and is particularly concerned with the provision of a self-contained driving unit for such machines.

. In operating a sewing machine, it is necessary that the speed be variable, ranging all the way from rest to a certain maximum, and always under the instant control of the operator. Where a small electric motor is used as the source of power, a rheostat is commonly employed. to effect this speed variation, but such a rheostat is relatively expensive and likely to get out of order, so that it has been proposed to use a constantspeed motor running without interruption throughout its period of use, and to vary the speed oi? the sewing machine by varying the tension on the driving belt, where a belt drive is used, or the pressure of the motor upon the handwheel of the machine where a friction drive is used; these variations to be effected by moving the motor bodily toward and away from the machine. Motor drives of this general nature are shown in my Patents Nos. 1.377.018 and 1,435,934, and in the patents to Curry No. 1,180,109, and Beach No. 1,272,189. In each of these the motor is pivoted either on the frame of the machine 7 itself, or on the table, and swung into and out of driving position by means of a treadle connection. When the motor is moved into complete non-driving position, a brake is usually provided for arresting further rotation of the machine; such brakes are well shown in Patents No. 1,180,109 and 1,435,934.

In all of these older driving systems, the motor has in some way been affixed to the machine or its table and generally pivotally mounted. It is an object of the present invention to improve upon this arrangement by making the driving unit entirely separate i from either the machine or its table, and designing the motor to move vertically in a any commercial sewing machine. The motor is supported'upon two vertical guideways fixed to the base ofthe standard and moves thereon in a straight line into and out of operative 1 position. By this arrangement, I

attain a three-fold advantage: the motor and its moving mechanism are situated be- 5 low the table and out ofthe operatorsway;

the movement of the motor is'in a straight line and not in an arc as is the case when pivoted (this results in a pull upon the driving belt which is independent of the length ofthat member) and the whole unit is selfcontained, compact, simple and durable, and

is readily positioned and removed.

I have also provided an adjustable stop I for the treadle limiting its downward swing.

When the drive. is of the gravity type, such 'as shown in my. two patents noted above, this stop prevents a depression of the treadle beyond that pointwhere the motor is exerting its full weight upon the driving belt (or i i in the case'of the friction drive upon the hand-wheel of the machine). Further downwardmovement wouldmerely waste the operators energy and do no good. lVhen the drive. is of the ositive pull type, such as shown in the Curry patent supra, the position of this stop determines the maximum pull which can be exerted, through the motor. on the belt.

It is a further'objectof the present invention,;to improve upon and adapt tothe present typeof driving unit, the automatic brake which stops the sewing machine concurrently withthemovement of the motor into full,

non-driving position. I have provided adjustahle means carried by the motor for contacting with the brake rod and so designed that the position of the driving unit can be altered within rat-her substantial limits with: Q I

out interfering with this contact. I have also provided'means operating in connection with thebrake for arresting the creeping o the belt when thebrake is applied.

The accompanying drawings disclose oer-Q tain preferred embodiments of my inven- .Aecordingly I provide a portable ins chine, the brake and driving belt being shown in their positions of use; Fig. 2 is an end elevation of the driving unit and machine shown in Fig. 1; Fig. 3 is an enlarged detail showing the relation of the motor to the brake and'the handwheel of the sewing machine; Fig. 4C is a plan View of the base of the standard of the driving unit, the treadle being removed; Fig. -5 is a section through one of the vertical guideways of the standard taken along line 5-5 of Fig. 2; and Fig. 6 is a sectional detail of the spring pin which a-ctuates the belt arresting mechanism. The. foregoing six figures show the invention used in connection with a motor drive of the gravity type. Fig. 7 is an end view similar to Fig. 2 but showing the present invention adapted for use in connection with a positive pull driving system; and Fig.8 is a still further modification showing the motor supported from the. lower side of the sewing machine table.

I shall first describe my invention as applied to a gravity driving system such as shown in Figs. 1 through 6, although many of the parts shown in these figures are identical with the parts shown in Figs. 7 and 8. ln the drawings, 1 represents any standard sewing machine provided with a hand-wheel or fly-wheel 2 a driving pulley 3. and mounted upon a table 4;. As shown in these drawings, this table is supported by wall brackets 53, but it is clear that the ordinary floor standards might well be employed. i j

The driving unit of the present invention is designed to be situated below the table of the machine, and comprises a small electric motor 6 provided with the ordinary driving pulley 7 mounted upon a standard R. This standard comprises a base 9 from which extend two vertical tubular members or guideways 11. The motor itself is fixed to and supported by two rods 12, which telescope withinthe guideways 11 and rest upon two compression coil springs 13 situated'in the base of these guideways. At the lower ends of the two tubular guideways, their inner and adjacent sidesare provided with longitudinal slots 1a through which pass the ends of a yoke 15. The ends of this yoke are positioned between the upper ends of the springs 13 and the lower ends of the rods 12. A treadle 16,15 pivoted at 17 upon the base of the standard and is connected by means of a link 18 with the yoke 15' so that depression of this treadle causes a compression of the two springs 13, thus permitting the rods 12 and the motor to move dhwnward under the influence of their own weight The downward swing of the treadle is limited by means of an adjustable stop 19, mounted upon thercar side of the base.

it shall now describe my improvedbrake and its operating mechanism with reference to Figs. 1 and It lounted upon the table 1, slightly beyond the driving pulley and handwheel of the machine, is 'asleeve 21 in which a brake rod 22 is designed to slide. Fear the upper end of this brake rod an arm extends laterally carrying at its outer end a brake shoe 23 designed to contact with the handwheel 2 of the machine. Extending upwardly from the upper end of the brake rod is a smaller rod 2% which terminates in a socket designed to receive a pin 26 about which is coiled an expansion spring 27 constantly urging the pin outwardly to maintain the position shown in Fig. 6. Fivoted to an extension on the outer end of the sleeve is a lever 28, one end of. which is designed to bear upon the driving belt and the other upon the outer end and head of the pin 26. Fixed to the upper face of the motor is a laterally extending arm 29 terminating in a threaded boss 31 in which there is mounted a set screw 32 provided with a wide flat head. 33. This set screw is designed to support the lower end of the brake rod 22 and is made wide andflat so that a nice positioning of the motor and its support will not be necessary in order to bring the brake rod into operative contact with its support. As the motor is moved. up the brake rod moves with it under the impetus of the common force and when the motor drops the brake rod likewise drops under the influence of gravity.

The driving unit just described is operated as follows: The standard and its motor are placed in position below the table of the sewing machine to be drivem care being taken that the driving pulleys of the machine and motor are in substantially the same plane. The driving belt is then slipped about he two pulleys and threaded through the holes provided For it. in the table. The brake rod 22 is raised and allowed to rest upon the head 3 of the set screw.. ln'its normal position, the motor must be raised so that the belt is too slack to drive the machine. At this point also the brake shoe must bear upon the periphery of the handwheel and the lever 28 hold the belt firmly against the pulley The belt must. therefore. be properly adjusted and the set screw 32 turned until the proper position of the brake is attained. Depression of the treadle now results in the compression of the springs 13. drop of the motor and the tensioning of the driving belt. hen the treadle has swung to such a position that the motor is hanging free and the rods 12 no longer contact with the ends of the yoke 15, the stop 19 is fixed to limit further downward movement of the treadle. As the motor drops under the a t on of its own weight, the brake rod drops and the machine begins to rotate. Upon releasing the pressure of the foot upon the lever, the springs 13 force the rods 12 and the motor upwardlly, lessening the tension upon the belt and slowing down the machine. hen the springs have expanded their full amount and the motor is in complete nondriving position, the brake has been applied and the lever 28 has, under the action of the spring pressed pin 26, clamped the belt firmly against the driving pulleys 28 of the machine, thus preventing its creeping under the influence of the still rotating pulley 7.

Referring now to Fig. 7 it will be seen that I have applied my present invention to a drive of the direct pull type. Instead of using the treadle to compress the springs 13 directly, and permitting the motor to fall of its own weight, I compress the springs through the intermediary of the motor itself; thus the treadle is directly connected to the motor by means of a linlr rod The stop 19 by limiting the downward swing of the treadle limits the maximum tension which the motor can exert upon the driving belt and thus fixes the maximum speed of the machine.

In Fig. 8 I have shown the motor support 236 depending from the table of the machine. in this form too, the springs 37 which urge the motor into non-driving position are tension and not compression springs. Except for these differences, the modification shown in F 8 operates precisely as that shown in F 7. In both of these figures, the showing of the brake has been omitted, but it is clear that the operation of the brake would be the same in these cases as in the case of the form of devices shown in Figs. 1 through 6.

The driving unit of the present invention is self-contained, and with the exception of the co-operating brake mechanism, can be used in connection with any commercial sew ing machine with no alterations whatsoever. It is merely slipped in place under the machine table, the proper adjustments made, and everything is in readiness for use.

I claim:

1. A driving unit for sewing machines comprising the combination of a standard adapted to be positioned adjacent the driving wheel of the machine, a motor mounted on the standard for vertical movement toward and away from the machine, and means for effecting such movement.

2. A driving unit for sewing machines comprising the combination of a standard adapted to be positioned below the machine, a vertical guideway forming part of the standard, a motor mounted for vertical movement on said guideway, and a treadle pivoted adjacent the guideway, movement of the treadle controlling the movement of them tor,

3. in a driving unit for sewing machines, the combination of a standard comprising a base and guideways thereon adapted to be positioned below the machine, a motor mounted on said guideways for vertical movement, a treadle pivoted on the base, springs urging the motor toward the machine, and means operated by the treadle for opposing the action of the springs.

A. driving unit for sewing machines comprising the combination of a base, two vertical tibular guideways thereon, expansion springs in the lower ends of said guideways, rods fitting within said tubular guideways and bearing against the springs, a motor carried by the rods, and a treadle pivoted upon the base, downward movement of the treadle compressing the springs and resulting in downward movement of the motor.

5. A support for a sewing machine motor comp-rising vertical telescoping members mounted upon a base, and means for extending and collapsing the members to move the motor toward and away from the machine.

6. A driving unit for sewing machines comprising the combination or a base, two vertical tubular guideways thereon, expansion springs in the lower ends of said guideways, rods fitting within said tubular guideways and bearing against the springs, a motor carried by the rods, a treadle pivoted upon the base, and means operated by the treadle for compressing the springs and permitting the motor to drop of its own weight.

7. A driving unit for sewing machines comprising the combination of a motor mounted for movement toward and away from the machine, a treadle controlling the movement of the motor and an adjustable stop limiting the swing of the treadle.

S. In a driving unit for sewing machines. the combination out a standard eo-m' rising a base and guideways thereon adapted to be positioned below the machine, a motor mounted on said guideways for vertical movement, a treadle pivoted on the base, springs urging the motor toward the machine, means operated by the treadle for opposing the action of the springs, and an adjustable stop on the base limiting the swing of the treadle in opposition to the springs.

9.-A driving unit for sewing machines comprising the combination of a base, two vertical tubular guideways thereon. expansion springs in the lower ends of said guideways, rods fitting within said tubular guideways and bearing against the springs, a motor carried by the rods, a treadle pivoted upon the base, downward movement of the treadle compressing the springs and resulting in downward movement of the motor, and an adjustable stop on the base limiting the downward movement of the treadle.

10. Av driving mechanism for a sewing machine comprising the coi'nbination of a motor designed to be held in operative relation to the machine by its own weight, litting means normally ho ding the motor in inoperative position, means independent ot the motor movable to counteract the effect of the spring and permit the motor to fall into operative position. and means arresting the movement of the counteracting means when the motor is in full operative position" 11. A driving mechanism tor a s-tewing machine comprising the combination of a motor designed to be held in operative relation to the machine by its own weight. a spring normally holding the motor in inoperative position, a treadle tor coinn'eracting the effect of the spring and permitting the motor to fall into operative position. and an adjustable stop tor l miting the movement of the treatlie when the motor has fallen into full operative position.

12. A driving unit for sewing machines comprising the combination ot a base, two vertical tubular gnideways thereon, expansion springs in the lower ends of said guideways, rods fitting within said tubular guideways and bearing against the springs, a motor carried by the rods, a treadle pivoted upon the base, means operated by the treadle for compressing the springs and permitting the motor to drop of its own weight, and an adjustable stop on the base for arresting the downward movement of the tre-adle when the motor has dropped a predetermined distance.

13. A driving unit for sewing machines comprising the combination of a standard adapted to be positioned adjacent the driving wheel of the machine. a motor mounted on the standard for vertical movement toward and away from the machine. means for citecting such movement, and means movable with the motor for operating a sewing machine brake.

14. The combination with a sewing machine of a constantly rotating motor, a driving belt by means of which the motor runs the machine, means for moving the motor toward and away from the machine to vary the tension ot the belt and consequently the speed of the machine. and means i'or positively arresting the movement of the belt- When the motor is moved into inoperative position.

15. The combination with a sewing machine of a constantly rotating motor. a driving belt by means of which the motor runs the machine, means for moving the motor toward and away from the machine to vary the tension of the belt and consequently the speed of the machine, a brake for arresting the rotation of the machine when the motor is moved into inoperative position. and spring pressed means for simultaneously bearing upon the belt to prevent creeping thereof 16. The combination with a sewing machine of a constantly rotat-itng driving motor, a belt by means of which the motor runs the machine, means for raising the motor toward and lowering it away from the machine to vary the tension of the belt, and consequently the speed of the machine, a brake for arresting the rotation of the machine when the motor is moved into inoperative position. a brake rod fixed to the brake and extending downwardly from the machine, and adjustable means carried by the motor for contacting with the brake rod and moving the brake into operative position as the motor is raised into inoperative position.

17. The combination with a sewing machine of a constantly rotating driving motor, a belt by means of which the motor runs the machine, means for raising the motor to ward and lowering it away from the machine to vary the tension of the belt, and consequently the speed of the machine, a brake for arresting the rotation of the machine when the motor is moved into inoperative position, a brake: rod fixed to the brake and extending downwardly from the machine. and a fiat headed. set screw carried by the motor for contacting with the brake rod and moving the brake into operative position as the motor is raised into inoperative position.

In testimony whereof I atfix my signature.

HYMAN MAIMIN. 

